1. Field of the Invention
This invention relates generally to air-evacuable travel bags and, more particularly, to improving the air impermeability of the one-way valve used to evacuate air from such bags.
2. Description of the Prior Art
It has been known to manufacture air-evacuable travel bags wherein a portion of the sidewalls thereof are heat sealed to one another to form one or more air-evacuation channels within the bag, typically along an edge thereof. The general object of such channels is to form a valve in the bag through which unwanted air is expelled from the bag when the sidewalls of the bag are pressed toward one another. The valve is preferably of sufficient length that ambient air pressure keeps the sealed sidewalls of the bag over the length of the valve together, which is intended to prevent air from re-entering the bag.
Unfortunately, the materials used in manufacture of the film forming the sidewalls of the bag, at least at a microscopic level, are of sufficient texture to prevent smooth wall-to-wall contact over the length of the valve under normal ambient air pressure conditions. As a result, over time, unwanted air tends to seep back into the bag. It would be desirable if an air-evacuable travel bag were provided with a valve that was resistant to such tendencies.